The present invention relates to spray booths for agricultural applications and, more particularly, to a spray booth for reproducible application of agrichemicals to plants.
Plant genomics is a highly complex science in which researchers determine the genetic makeup of a plant and correlate the genetic information with particular characteristics of the plant. To this end, it is desirable to minimize as many variances in the experimental parameters as possible in order to obtain more accurate genetic data on the plants.
Typical plant genomics research involves exploration of the interaction between the plant and various herbicides or pesticides which may be used on or around the plants in the field. Laboratory methods for investigating the effects of herbicides and pesticides on plants generally requires application of herbicides or pesticides, commonly referred to as agrichemicals, to numerous batches of samples of the plants to be used to conduct the genomics research. Accordingly, it is highly desirable for all samples in the individual batches to be treated with the agrichemical in as uniform and consistent a manner as possible. Currently, the agrichemical application process in the laboratory setting typically is performed using a handheld sprayer to manually apply the agrichemical to each batch of plant samples. However, manual application of the agrichemical tends to introduce large variances in the plant samples due to inconsistent coverage of the plants with the agrichemical and variable agrichemical application rates. For example, certain plants may have little or no coverage with the agrichemical while other plants may be doused. Further, it is often required that the agrichemical be applied as a substantially uniform surface coating on the plants. Consistent, uniform coverage and application rates produce more desirable test samples with little or no variance therebetween. In addition, in order to further reduce variances, the agrichemical should be applied with minimal physical impact upon the plants. Still further, plants at various stages of growth or plants of different heights may be treated with noxious agrichemicals, wherein the agrichemical must be cleaned up after application. Thus, a suitable agrichemical application system should be adaptable to these needs.
In light of the above requirements, there exist certain systems which are not particularly suited for the described purpose. For example, certain patents, such as U.S. Pat. No. 5,283,974 to Graf, Jr. and U.S. Pat. No. 3,943,658 to Hai, describe environmentally controlled chambers for plants. These patents generally describe watering systems within the chamber comprising a number of stationary nozzles for irrigating the plants therein. Stationary nozzles, however, will tend to provide an uneven and non-uniform coverage of the plants being sprayed.
In further detail, the Graf, Jr. ""974 patent discloses an environmentally controlled cabinet with a system for watering the plants contained therein through a plurality of misting heads located adjacent to the back panel of the central housing. However, because the misting heads are located in fixed positions adjacent to the back panel and thus are not evenly dispersed about the housing, the mist supplied by the stationary heads will have a defined water dispersion pattern which may not produce even and uniform wetting of the plants contained within the chamber for a given amount of water being sprayed. Further, in order to provide even and uniform coverage of the plants contained therein, a large excess of the liquid may be necessary to ensure saturation of the plants being sprayed.
Similarly, the Hai ""658 patent discloses an apparatus for providing a controlled environment for intensive cultivation of vegetable matter. A single water spray inlet is located in the roof of the growing chamber above each of a plurality of cultivation boxes. The disclosed apparatus thus provides a central water spray mechanism disposed over a rectangular cultivation box. However, this centralized water spray mechanism may still fail to provide uniform and even watering of the plants contained within the cultivation fail to provide uniform and even watering of the plants contained within the cultivation box, especially about the corners thereof.
Further, the noted patents both relate to the supply of water to plants which can have different parameters than the supply of agrichemicals to plants. For example, the uniform application of a liquid to the leaves of the plants is more important with agrichemicals than with water, which can be supplied to the soil in which the plants are growing. Accordingly, an even application of water to the leaves of the plants in the Graf, Jr. ""974 and Hai ""658 patents is not as important as with the agrichemicals according to the present invention.
Thus, there exists a need for an apparatus and a corresponding method for applying an agrichemical, such as a herbicide or a pesticide, to plants in a highly uniform and controllable manner. This apparatus and method should preferably enable the application of agrichemicals as an even surface coating on the plants and should allow the agrichemical application to be accomplished with high consistency between successive batches of plant samples. The apparatus and method should further allow various sizes and shapes of plants to be treated while causing minimal physical impact on the plants. In addition, the apparatus and method should preferably allow any residual noxious fumes or vapors of the agrichemical to be exhausted away from the apparatus in a safe manner. It is further desirable that the apparatus and method be non-reactive with the agrichemical and also capable of being easily cleaned.
The above and other needs are met by the present invention which, in one embodiment provides a spray booth for reproducible application of agrichemicals to plants comprising a support member for supporting a plurality of plants, a cover having a plurality of sides and a top and forming an enclosure with the support member for enclosing the plants therein, an agrichemical source for providing a pressurized agrichemical, and a spray arm having a spray mechanism operably connected to the agrichemical source. Preferably, the spray arm is disposed within the enclosure and over the support member such that it extends across the width of the support member. The spray mechanism is used for spraying a predetermined amount of the agrichemical therefrom in the form of a fine mist along the length of the spray arm. Advantageously, at least one of the support member and the spray arm is laterally moveable relative to the other such that the plants disposed both lengthwise and widthwise on the support member are substantially uniformly misted with the agrichemical.
A spray booth according to embodiments of the present invention may further include an exhaust hood operably connected to the enclosure for exhausting agrichemical fumes from within the enclosure. Further, at least one of the support member and the spray arm may be moveable in relation to the other to vary the distance therebetween to accommodate plants of various heights on the support member. The support member may also be comprised of a mesh grate or other open porous structure to allow the passage of excess amounts of the agrichemical therethrough. In certain instances, the spray booth may further include a drain pan disposed below the support member to receive excess amounts of the agrichemical therein. In addition, at least a portion of at least one of the sides of the enclosure may be transparent for allowing visual monitoring of the application of the agrichemical to the plants.
The plurality of plants is typically disposed in at least one flat comprising an interconnected array of receptacles. According to one embodiment of the present invention, the spray booth is capable of accommodating up to four flats. According to a preferred embodiment of the present invention, the support member supporting the plants is stationary while the spray arm is adapted to move bidirectionally in a substantially horizontal plane thereabove. In an alternate embodiment, the spray arm is stationary and the support member supporting the plants is adapted to move bidirectionally in a substantially horizontal plane therebelow, wherein the support member may comprise, for example, a conveyor. Thus, the relative movement between the spray arm and the support member provides for substantially uniform misting of the plants with the agrichemical. Further, the pressure and the amount of the agrichemical provided for application to the plants are adjustable to promote the substantially even application of the agrichemical to the plants.
Another advantageous aspect of the present invention comprises a method for reproducibly applying agrichemicals to plants. The first step comprises enclosing a plurality of plants disposed on an underlying support member and a spray arm having a spray mechanism in an enclosure. Preferably, the spray arm is disposed above the support member and adapted to extend thereacross. A predetermined amount of an agrichemical is then sprayed through the spray mechanism such that the agrichemical is misted onto the plants. Simultaneously, at least one of the support member and the spray arm is moved relative to the other in a substantially horizontal plane through at least one cycle to substantially uniformly mist the plants disposed both lengthwise and widthwise on the support member with the agrichemical. Preferably, one cycle comprises misting the plants along the length of the support member in a first direction and then misting the plants along the length of the support member in a second direction which is generally opposite to the first direction.
Thus, it will be appreciated that embodiments of the present invention enable uniform, consistent, and reproducible application of agrichemicals to growing plants of various sizes. The application of the agrichemical in the form of a mist provides for substantially uniform surface coverage while minimizing physical impact on the plants. The movable spray arm and/or support member, in addition to the ability to adjust the spacing therebetween, enhances the uniformity of agrichemical application while allowing the apparatus to accommodate plants of various sizes. Uniform and consistent application of agrichemicals is particularly advantageous in a laboratory setting where highly controlled experimental conditions are necessary to reduce variations and to facilitate interpretation of gathered data. Accordingly, by controlling and automating the amount and the manner in which the agrichemicals are applied to the plants, subsequent batches of plants can be treated with agrichemicals under substantially the same conditions as previous batches. Minimizing variations in the agrichemical application process is especially advantageous, for example, in plant genomics research where it is highly desirable to have uniformly treated plant specimens on which to perform experiments. Highly controlled experimental conditions further provide a method for readily identifying variations in the conditions to which the plant specimens are exposed. An exhaust hood and simple construction with non-reactive materials further permits noxious agrichemicals to be applied while facilitating cleaning upon completion of the agrichemical application process. It will be recognized, therefore, that the invention facilitates the achievement of distinct advantages over prior art plant spraying devices.